Tubs-stripping machine



C. E. MAYNARD.

TUBE STRIPPING MACHINE.

APPLICATION man JUNE 6.1921.

Patented Jan. 3, 1922.

3 $HEETS$HE-ET I:

INVENTOR C/f/AALfS EDGAR MAYNARD W I ATTORN Y i c. E. MAYNARD. TUBE STRIPPING MACHINE.

APPLICATION FILED JUNE 6.1921.

1,402,171, Patented Jan. 3, 1922,

3 SHEETS-SHEET 2- 114. A; 3a H 102 gul INVENTOR CHARLES EDGAR MAYA/AR!) ATTORNEY C'. E. MAYNARD.

TU'BE STRIPPING MACHINE. APPLICATION nmuuma 6.192t.

1,402,171, 4 Patented Jan. 3,1922.

3 SHEETS-SHEET 3.

INVENTOR CHARLES EDGAR MAYNARD ATTGRNEY v UNITE FEE.

CHARLES EDGAR MAYNARD, OF NORTHAMPTON, MASSACHUSETTS, ASSIGNOR TO THE FISK RUBBER COMPANY, OF CHICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

TUBE-STRIEPING LJIACHXNE.

' Application filed June 6,

To all 10 7: am it may concern Be it known that 1, CHARLES EDGAR MAY- NARD, a citizen of the United States of America, residing at Northampton, in the county of Hampshire and State of Massachusetts, have invented certain new anduseful Improvements in a 'iube-Stripping Machine, of which the following is a specification.

My invention relates to a machine and process for stripping rubber tubes from tube forming mandrels; more especially to the stripping of vulcanized rubber inner tubes, used as air containers for pneumatic tire casings, from circular mandrels.

The object of my invention is to provide a faster, cheaper and more satisfactory method of stripping tubes from circular mandrels than has heretofore been employed.

My invention will now be explained with reference to the accompanying drawings; in which,

Fig. 1 shows a side view of my machine;

Fig. 2 shows a front view, partly in section, of my machine with a mandrel in place ready for the tube to be stripped;

Fig. 3 is a plan view of an air ring through which I introduce air pressure underneath a turned back portion of a tube on a mandrel;

Fig. 4; shows a plan view of my machine and driving means with the air-ring detached;

Fig. 5 shows a plan view of the connection by which the mandrel is coupled to the means for rotating it, taken on plane Y Y of Fig. 2;

Fig. 6 is a front view of Fig. 5 on plane X X of Fig. 2;

Figs. 7, 8, 9, and 10 are diagrammatic views showing four stages in the stripping of a rubber tube from a circular mandrel.

My invention will be more clearly explained by taking three diflerent elements; the driving mechanism, the mechanism for holding and allowing a mandrel to rotate, and the mechanism for supplying the air used for blowing the tube; and then showing how these three operate in combination to accomplish my purpose.

I employ a small motor 10 as a prime mover and transmit power to a shaft 12 through a gear box 14. Splined to the shaft- 12 is the male portion 16 of a friction clutch Specification of Letters Patent.

Patented Jan. 3, 1922.

1921. Serial No. 475,220.

operating with a female clutch portion 18 which is keyed to a shaft 20; a brake drum 19, on the shaft20, acts in conjunction with a friction brake arm 22, which is pivoted at to a bracket 26.

The clutch and brake mechanisms are controlled by a pedal 28 located at an end of an arm 30 which is hinged to the main frame 32 at 3%. Pivoted to the arm 30 are two rods 36 and 88. Rod 86 has its upper end 10 pivoted to the brake arm 22 and upon upward motion of the arm 30 actuates the brake arm 22 against the brake drum 19. Upon upward motion of arm 30, the rod 38, having on one side the rack 4-2, actuates a gear id. The gear l meshes with a rack 46 slidable in bearings &8. A bifurcated element 50 extending partially around the groove 52 of the male clutch element 16 is fixed to the rack 6 at 5 1. Gear id, through the rack 16 and the bifurcated arm 50 actuates the male clutch portion 16 longitudinally on the shaft 12.

During the cycle of operations of my machine it is desirable that the clutch and brake mechanisms be held in the three following positions relative to one another; clutch out and brake oil, clutch in and brake off, and clutch out and brake on. These three positions are easily determined by the operator y pressing down the foot pedal 28 until a pawl 58 on the arm 30 engages with the proper notch on a bracket 60 (relative to the above named positions as shown by the notches 54, 52 and 56). The operator governs the pawl 58 by means of the foot pedal 68, connected to the pawl by the rod 61.

A gear 62, keyed to the shaft 20, meshes with a gear 6 1 which is keyed to a shaft 66. The shaft 66 is supported by a bearing 68 and has a reduced threaded portion 70 at its forward end. A sleeve 72 having a flange 73 and a circular groove 7 5 is splined at 77 to the shaft 66. Upon the sleeve 72 is an arm 74 having a pin receiving end 76 through which a pin 78 may be inserted. A hand wheel 80 is rigidly connected to a nut 82 which engages with the threaded portion 70. A key 84:, which is easily removable and engages in any of the longitudinal slots 86 on the shaft 66 as well as in the slot 88 of the nut 82, holds the wheel 80 in any desired adjusted position on the threaded portion 70. A. plurality of arms 90, rigidly fixed to the wheel 80, have flanges 91 engaging in the circular groove 75. From the foregoing description it is easily seen that the arm 74 may be adjusted as desired along the shaft 66 by the hand wheel 80.

The mandrels 92 which I employ are of the circular type and have a circumferential gap 94 in order to allow the rubber tube 96 to be conveniently placed upon and taken off the mandrel. The mandrel has a transverse air tight wall 98 at one end which prevents compressed air, which is used for purposes to be described later, from escaping around the inside of the mandrel. At the other end of the opening is a lug 100 having a hole therein to receive the pin 78.

I rotatably support the mandrel 92 upon which a rubber tube 96 is mounted, by a plurality of rollers 102. The rollers rotate about pins 104 which are supported by bearings 106 and which are rigidly bolted, as shown by 108, to the main frame. The different sizes of mandrels employed in vulcanizing tubes have a uniform inner circumference 110, but varying outer circumferences 112. For this reason the pins acting as bearing for the rollers 102, which are in contact with the outer circumference 112, are adjustable along the slots 114 in the main frame 32 in order to accommodate different sized mandrels.

As a means for holding a turned back end of the rubber tube and a means for introducing air pressure underneath that turned back portion, I employ an air-ring 116 hinged at 118 with respect to the main frame 32 by means of the bracket 120 in order to allow it to be swung up out of its normal position into a position shown in dotted lines on Fig. 1. The inside diameter of the air-ring is of such size as to allow a mandrel, upon which a tube is mounted, to pass unobstructed through the ring and still cut down all unnecessary clearance. The outside face 122 of the air-ring is beveled to receiie a rubber tube end 124 which is turned back and held in position over the outside of the air-ring by a ring 126 bev eled on its inside. .A plurality of air ports 128 conduct compressed air from any convenient outside source to the pocket 130 formed by the turned back tube.

A circular flexible hoop 132 angular in cross-section, which I will term a sealing ring, has one side 134 attached to the airring while the other side 136 fits snugly around the tube 96 which is mounted upon the mandrel. The purpose of the hoop is to prevent any leakage of air between the air-ring and the rubber tube on the mandrel when air is upplied under pressure to the pocket 130. A flange 138 (Fig. 1) on the upper part of the air-ring cooperates with a latch 140, pivoted to the main frame at 142, to hold the air-ring up out of normal position when required.

The procedure in stripping a tube from a circular mandrel is as follows: The mandrel 92, upon which a rubber tube 96 is mounted, is placed in position on the rollers 102 as shown in Fig. 2; the foot pedal 28 has it pawl 58 in position 54, in order that the arm 74 may be easily swung around in position by hand to insert pin 7 8 through a pin receiving hole in the lug 100. The rubber tube is turned back at 124 by hand over the outside beveled portion 122 of the air-ring 116, and the ring 126 is clamped over the outside beveled portion of the airring so that the edge of the rubber is held firmly between the two beveled surfaces.

The clutch 16 is now thrown in by engaging the pawl 58 in position 52. The arm 74 is mechanically rotated by the previously described mechanism and rotates the mandrel 92 upon the rollers 102. As the mandrel rotates, air pressure is introduced from any convenient outside source through the air ports 128 and into the pocket 130 formed by the turned back portion of the tube. Since the rubber tube is gripped at 124 to the non-rotatable air-ring, the tube will be stripped back upon itself as the mandrel is rotated, the air pressure in the pocket formed by the turned back portion of the tube acting as a lubricant. Figs. 7, 8, 9, and 10, show four positions of the rubber tube as it is being stripped from the mandrel. The arm 74 is rotated until it assumes the positions shown by Fig. 9. By this rotation of the arm the tube 96 is stripped back to the point 138. The ma chine is then stopped by pressing the foot lever 28 until pawl 58 engages in the notch 56. At this position the clutch is disengaged and the brake arm 22 is bearing against the brake drum 19, thereby holding the arm 74 and therefore the mandrel 92 from turning. As the arm 74 terminates its rotation in the position as shown by Fig. 9, the air-ring i in a position in the circumferential ga 94. The outside ring 126 is then remove thereby releasing the end of the rubber tube, and the air-ring 116 is turned up out of the way as shown in Big.

After a tube has been about half stripped from a mandrel it is pulled off by hand over the remaining portion of the mandrel. When the air-ring 116 has been swung up out of the wa the end 142 of the rubber tube 96 exten ing over the gap 94 is gathered together by hand and air under pressure is introduced inside the tube as by inserting a pipe 144 within the end of the tube and gathering the tube about it. As the pressure is a plied inside the tube, the tube is pulled o the mandrel by the operator. The mandrel is now taken from the rollers and a new mandrel is put in its place ready to have a tube stripped.

From the foregoing description it is evident that the complete stripping operation can be accomplished by one man. The operation is fast and gives a transversely uniform pull on the tube, as it is being pulled back. The machine is adapted to strip different sized mandrels and is very satisfactOIg in operation.

aving thu described my invention, I claim:

1. In a tube stripping machine, means for supporting a circular mandrel; means for holding a turned back portion of a rubber tube mounted upon the mandrel; and means for causing a relative motion between the mandrel and the said holding means.

2. In a tube stripping machine, a frame, a plurality of rollers supported by the frame and adapted to rotatably support a circular mandrel; means for rotating the circular mandrel; means for holding a turned back portion of a rubber tube which is mounted upon the mandrel; means for forming a pocket between the portion of the tube turned back and a portion of the tube on the mandrel and means for supplying a fluid under pressure to the pocket.

3. In a rubber tube stripping machine, mean for holding a turned back portion of a rubber tube which is mounted upon a mandrel; means for forming a pocket between the turned back portion and a portion of the tube upon the mandrel; means for supplying fluid under pressure to the said pocket; and means for causing a relative movement between the mandrel and the turned back holding means.

4. In combination with a rubber tube stripping machine, a ring adapted to transversely encircle a rubber tube mounted upon a mandrel and adapted to grip a turned back end of the tube; means for making a pocket formed by the turned back portion substantially air tight, and means whereby a fluid under pressure may be supplied through the ring'to the pocket.

5. A. process of stripping rubber tubes from circular mandrels consisting of turning back an end of the rubber tube upon itself, gripping the turned back portion and forming a substantially air tight joint between the turned back portion and the tube upon the mandrel; introducing fluid under pressure into the pocket formed by the turned back portion and at the same time causing a relative movement between the mandrel and the tube gripping means.

6. A process of stripping rubber tubes from mandrels consisting of turnin back a portion of the rubber tube upon itself, gripping the turned back portion a well as forming a substantially air tight joint between the turned back portion and that part of the tube on the mandrel; introducing a fluid under pressure to the pocket formed by the turned back portion and causing rel ative movement between the mandrel and the tube gripping means.

7. An air-ring constructed to pass overa rubber tube mounted upon a mandrel, the outside surface of the air ring being beveled and adapted to receive a turned back portion of the tube; a ring beveled upon the inside, adapted to fit over the beveled out side portion of the air-ring and over the turned back tube portion to hold the tube tightly in place on the outside of the airring; at least one port in the air-ring through which air may be supplied from an outside source to that portion of the airring enveloped underneath the turned back tube, and an air sealing ring fixed to the air-ring and having its inside surface fitting snugly against the tube in order to prevent air introduced under pressure through the ports from escaping between the airring and the tube mounted on the mandrel.

8. In a tube stripping device, a ring adapted to encircle a mandrel upon which a rubber tube is mounted, means for holding a turned back portion of the tube against the ring, and one or more orts in the ring adapted to introduce a fluid from an outside source to the pocket formed by the turned back tube portion.

CHARLES EDGAR MAYNARD. 

